Can a marriage survive if a husband and wife disagree on what it means to be a good person?

How to Be Good. By Nick Hornby. Riverhead, 305 pp., $13, paperback.

By Janice Harayda

Not long ago, the New England Journal of Medicine published the results of a study that found that if you get fat, your close friends tend to gain weight, too. Something like this principle drives the third novel by Nick Hornby, the author of High Fidelity and About a Boy and the memoir Fever Pitch.

Katie Carr, an English doctor, has to reconsider her ideas about what it means to “a good person” after her 41-year-old husband, David, falls under the influence of a spiritual guru named D.J. GoodNews. This premise might sound like the set-up for a variation on that bedraggled cliché, an overprivileged couple’s midlife crisis.

But How to Be Good is a novel of ideas that is less about a marriage in trouble than about the question implicit in its title: What does it mean to be “good” in a materialistic age? Does it involve helping people through your work, as Katie imagines? Or does it require sacrifices such as giving away a family computer, as David insists after his abrupt spiritual conversion? If two people disagree on the answer, can they stay together?

As it parses these questions, How to Be Good shifts from satire to farce, and at times the characters resemble intentional caricatures. But Hornby maintains suspense about fate of Katie and David’s marriage until the last pages and invests their plight with enough comedy that the novel doesn’t turn into a sermon. And even his one- or two-liners often have a sly wisdom. In the first scene, Katie calls David on her cell phone to say she wants divorce, then tries to rationalize her behavior as atypical.

“But for the majority of people, marriage-ending conversations happen only once, if at all,” she reflects. “If you choose to conduct yours on a mobile phone, in a Leeds car park, then you cannot really claim that it is unrepresentative, any more than Lee Harvey Oswald couldn’t really claim that shooting presidents wasn’t like him at all. Sometimes we have to be judged by our one-offs.”

Best line: “Sometimes we have to be judged by our one-offs.”

Worst line: It’s unclear whether the lack of punctuation and subject-verb agreement in the following are intentional: “Whenever I have seen Jerry Springer, the guilty party always says to the devastated spouse ‘I tried to tell you we wasn’t happy, but you wouldn’t listen.’ And I always end up thinking that the crime of not listening does not automatically deserve the punishment of infidelity.”

Recommendation? A good book club book. More than most comic novels, How to Be Good raises the moral questions that could help to foster a lively discussion. And the slackers who never finish the book may have seen a movie version of one of Hornby’s other novels, so they won’t feel completely left out of the conversation.

Published: July 2001 (Riverhead hardcover), May 2002 (Riverhead paperback) us.penguingroup.com. Hornby’s latest novel is A Long Way Down (Riverhead, 2005).

Links: You can read about Hornby and download the first chapter of How to Be Good athis official site,www.nicksbooks.com. Visit the Internet Movie Database www.imdb.com for information on the movie versions of Fever Pitch, High Fidelity and About a Boy). Search for “Nick Hornby” on British Council site www.contemporarywriters.com for a biography, critical analysis and a list of his awards.

Caveat lector: I haven’t read Hornby’s earlier novels or Fever Pitch, which many of his fans prefer to How to Be Good.

Janice Harayda www.janiceharayda.com is an award-winning critic who has been the book columnist for Glamour, book editor of the Plain Dealer and a vice-president of the National Book Critics Circle www.bookcritics.org. She wrote the comic novels The Accidental Bride (St. Martins, 1999) and Manhattan on the Rocks (Sourcebooks, 2004).